The protein encoded by this gene removes 5" overhanging flaps in DNA repair and processes the 5" ends of Okazaki fragments in lagging strand DNA synthesis. Direct physical interaction between this protein and AP endonuclease 1 during long-patch base excision repair provides coordinated loading of the proteins onto the substrate, thus passing the substrate from one enzyme to another. The protein is a member of the XPG/RAD2 endonuclease family and is one of ten proteins essential for cell-free DNA replication. DNA secondary structure can inhibit flap processing at certain trinucleotide repeats in a length-dependent manner by concealing the 5" end of the flap that is necessary for both binding and cleavage by the protein encoded by this gene. Therefore, secondary structure can deter the protective function of this protein, leading to site-specific trinucleotide expansions.
Base Excision Repair, organism-specific biosystem; Base excision repair, organism-specific biosystem; Base excision repair, conserved biosystem; Cell Cycle, organism-specific biosystem; Cell Cycle, Mitotic, organism-specific biosystem; Chromosome Maintenance, organism-specific biosystem; DNA Repair, organism-specific biosystem;
5-3 exonuclease activity; 5-flap endonuclease activity; 5-flap endonuclease activity; DNA binding; damaged DNA binding; double-stranded DNA binding; double-stranded DNA specific exodeoxyribonuclease activity; endonuclease activity; exonuclease activity; magnesium ion binding; manganese ion binding; protein binding; ribonuclease H activity;